Discuss the steps involved in designing a quality control system. (answer with 50-65 words.)

1. The first step in designing a quality control system is to identify the critical points in each process where inspection and testing are needed. The guidelines for doing this are as follows: Ensure that incoming raw materials or purchased services meet specifications. Ide- ally, incoming inspection can be eliminated, or reduced to sampling, by certifying the supplier. Supplier certification is normally granted to suppliers that have dem- onstrated they use statistical process control (SPC) and other methods to achieve consistent quality performance. In this case, the products or services of the supplier can be used with confidence by the customer. Inspect products or services during the production process. As a general rule, the product or service should be inspected by operators before irreversible operations take place or before a great deal of value is added to the product. In these cases, the cost of inspection is less than the cost of adding more value to the product. A precise determination of where in the process the product or service should be inspected should be made from the process flowchart. The third critical inspection point is the finished product or service. In manufactur- ing, final products are frequently inspected or tested before shipping or before the product is placed in inventory. At an automobile assembly plant, for example, a random sample of cars is taken directly off the assembly line and thoroughly in- spected for appearance and function. The defects are noted and fed back to assembly- line personnel so that they can correct the underlying causes. The defects are also used to compute a quality score for comparison among assembly plants. It is usually far better to prevent defects from occurring than to inspect and correct de- fects after production. Nevertheless, some measurement via sampling inspection is nec- essary to maintain processes in a continuous state of statistical control and to facilitate improvement. Thus, inspection cannot be eliminated, but it can be reduced by a vigor- ous process of prevention. 2. The second step in designing a quality control system is to decide on the type of mea- surement to be used at each inspection point. There are generally two options: measure- ment based on variables or attributes. Variables measurement utilizes a continuous scale for product and service charac- teristics such as time, length, height, and weight. Examples of variables measurement are the dimensions of parts, the viscosity of liquids, and the time it takes to answer a customer service call. Attribute measurement uses a discrete scale by counting the number of defective units or the number of defects per unit. When the quality specifications are complex, it usually is necessary to use attribute measurements. For example, a laptop may be classified as defective if it fails any of a number of functional tests or if the appearance of the display is not satisfactory. In inspection of cloth, a defect can be defined as a flaw in the material and the number of defects per 100 yards can be counted during inspection. Determining the type of measurement to use also involves the specification of measuring equipment. 3. The third step in defining the quality control system is to decide on the amount of in- spection to use. Generally, a production process that is in statistical process control minimizes the amount of inspection needed. Exceptions to this might be when process variables are difficult to define or when the consequences of failure are very high. For example, when human lives are at stake, both process control and inspection of every production unit may be used. 4. The final step in designing a quality control system is deciding who will do the inspec- tion. Usually, it is best to have workers inspect their own output and be responsible for the quality of their work (called quality at the source). A prevention program, along with worker responsibility for quality, will be less expensive than an extensive inspec- tion program. In high-contact services there is no choice but to have quality at the source, since the customer immediately perceives defects. In some cases, the customer will be involved in inspecting the product or service. Some business customers station inspectors at suppliers' plants to examine and accept or reject shipments before they are sent on to the customer. The government has inspec- tors in a variety of industries to ensure quality in the interest of public health and safety, for example, in the food supply chain. A well-designed quality control system requires a series of management judgments and the participation of all functions. The control principles themselves are elementary